@inproceedings{DoehringZeisingStieglitzetal.2022, author = {D{\"o}hring, Thorsten and Zeising, Sebastian and Stieglitz, Veronika and Burwitz, Vadim and Rukdee, Surangkhana and Friedrich, Peter and Jelinek, Martin and Hudec, Rene}, title = {R{\"o}ntgenteleskop-Funktionstests durch Beobachtung astronomischer Objekte am sichtbaren Nachthimmel}, series = {DGaO Proceedings}, volume = {2022}, booktitle = {DGaO Proceedings}, publisher = {DGaO}, organization = {TH Aschaffenburg}, issn = {1614-8436}, pages = {1 -- 2}, year = {2022}, abstract = {Lobster-Eye-R{\"o}ntgenteleskope nutzen reflektierende Planspiegel unter streifendem Einfall und zeichnen sich durch ein großes Beobachtungsfeld aus. Die Spiegel reflektieren auch sichtbare Strahlung hervorragend. Nach R{\"o}ntgen-messungen im Labor wurden nun weitere Tests durchgef{\"u}hrt, um die Abbildungs-eigenschaften mit realen Objekten des sichtbaren Himmels zu untersuchen.}, subject = {R{\"o}ntgenteleskop}, language = {de} } @inproceedings{HudecGilleGuimbelotetal.2022, author = {Hudec, Rene and Gille, Florian and Guimbelot, Elzear and Tichy, Vladimir and D{\"o}hring, Thorsten}, title = {Effective areas of astronomical X-ray optics for cubesats and rocket experiments}, series = {DGaO Proceedings}, volume = {2022}, booktitle = {DGaO Proceedings}, number = {123}, publisher = {DGaO}, organization = {Technische Universit{\"a}t Prag}, issn = {1614-8436}, pages = {1 -- 2}, year = {2022}, abstract = {The effective area is one of the main telescope parameters when justifying real space application. We discuss the estimation of the effective collecting area of an X-ray telescope by two different methods, an analytical method and a simulation algorithm, and then compare the results. The Lobster Eye type telescopes considered here are designed for rocket experiments and CubeSat flights.}, subject = {R{\"o}ntgenteleskop}, language = {en} } @misc{HudecGilleGuimbelotetal.2022, author = {Hudec, Rene and Gille, Florian and Guimbelot, Elzear and Tichy, Vladimir and D{\"o}hring, Thorsten}, title = {Effective areas of astronomical X-ray optics for cubesats and rocket experiments}, publisher = {DGaO}, organization = {TH Aschaffenburg}, pages = {1 -- 1}, year = {2022}, abstract = {We address the problem of estimation the sensitivity of astronomical X-ray telescopes of Lobster Eye type , with emphasis on calculation of effective areas for telescopes designed for rocket and CubeSat flights. This parameter is one of the principal parameters when justifying the real space application. Indeed, the larger the effective area is, the more efficient the optical system is, able to provide images of fainter and more distant celestial targets. We discuss the estimation of the effective collecting area of a X-ray telescope by two different methods and then compare the results: the analytical method and then the simulation algorithm.}, subject = {R{\"o}ntgenteleskop}, language = {en} } @inproceedings{DoehringStieglitzHudecetal.2022, author = {D{\"o}hring, Thorsten and Stieglitz, Veronika and Hudec, Rene and Sapsai, Iryna and Friedrich, Peter and Burwitz, Vadim}, title = {Characterization of a lobster-eye type X-ray telescope}, series = {EOSAM-Conference}, volume = {2022}, booktitle = {EOSAM-Conference}, organization = {TH Aschaffenburg}, pages = {1 -- 1}, year = {2022}, abstract = {Lobster-eye type X-ray telescopes use reflecting plano mirrors under grazing incidence and can observe a large field of view. As part of a Bavarian-Czech cooperation, two telescopes were build, equipped with mirrors coated with gold and iridium. Their X-ray characterization was carried out at the PANTER test facility, which simulates parallel starlight incident on the telescopes. The telescopes have an angular resolution of about 4 arc minutes in X-rays and a focal length of about 2 meters. The used X-ray mirrors reflect and focus visible light as well; their functionality in the optical regime was checked in laboratory tests. Now another test campaign will be carried out to examine the telescope resolution for real objects of the visible night sky and the imaging properties for star constellations.}, subject = {R{\"o}ntgenteleskop}, language = {en} } @inproceedings{HudecPomahačStaniketal.2023, author = {Hudec, Rene and Pomahač, Vit and Stanik, Eva and D{\"o}hring, Thorsten and Schilling, Klaus}, title = {Space Telescopes based on Satellite Tandem Flights}, series = {DGaO Proceedings}, volume = {2023}, booktitle = {DGaO Proceedings}, issn = {1614-8436}, pages = {2}, year = {2023}, abstract = {Progress in satellite control engineering enables tandem flight arrangements of mini-satellites in future space missions. Cost effective CubeSat technologies offer an interesting possibility for space-born telescope payloads. Two small satellites will carry the telescope optics and the detector system, respectively. Related formation flight requirements could be transferred from the NetSat-Mission.}, subject = {R{\"o}ntgenteleskop}, language = {en} } @misc{HudecPomahacDoehringetal.2023, author = {Hudec, Ren{\´e} and Pomahac, Vit and D{\"o}hring, Thorsten and Stanik, Eva and Klaus, Schilling}, title = {Space Telescopes based on Satellite Tandem Flights}, series = {DGaO Jahrstagung}, volume = {2023}, journal = {DGaO Jahrstagung}, publisher = {DGaO}, organization = {Technische Hochschule Aschaffenburg}, pages = {1 -- 1}, year = {2023}, abstract = {Due to the recent progress in satellite control engineering, tandem flight arrangements of mini-satellites are currently in discussion and under consideration for future space missions. CubeSat technologies offer an interesting possibility for space-born telescope payloads based on this approach. In such a scenario, two small satellites will fly at a constant distance of a few meters up to 100 meters. Thereby, the front satellite will carry the telescope optics and the second satellite the detector system. Related formation flight requirements were addressed in the NetSat-Mission, composed of four 3U-CubeSats, launched 2020. Space technology challenges concern in particular orbit control by an appropriate propulsion system as well as precision attitude pointing towards the joint target, and could be transferred from the NetSat-mission to the proposed Tandem Mission. This will allow space-based telescopes with a long focal length even placed on board of small or miniature CubeSat-type satellites. Cost effective Kirkpatrick-Baez type X-ray telescopes represent an important application here as they have longer focal lengths compared to previous astronomical observatories using Wolter I type X-ray mirrors.}, subject = {R{\"o}ntgenteleskop}, language = {en} } @inproceedings{DoehringStieglitzFriedrichetal.2023, author = {D{\"o}hring, Thorsten and Stieglitz, Veronika and Friedrich, Peter and Burwitz, Vadim and Jelinek, Martin and Hudec, Rene}, title = {Testing of lobster-eye type telescopes with X-rays and visible light}, series = {SPIE Proceedings}, volume = {2023}, booktitle = {SPIE Proceedings}, number = {12576}, publisher = {SPIE}, organization = {TH Aschaffenburg}, doi = {https://doi.org/10.1117/12.2665429}, pages = {1257606-1 -- 1257606-5}, year = {2023}, abstract = {Reflective coatings for astronomical X-ray optics were developed at the "Aschaffenburg Competence Center for Astronomical and Space Instrumentation" (ACCASI) since several years. As part of a Bavarian-Czech cooperation between the Technical University of Aschaffenburg and the Czech Technical University of Prague, now two mechanically identical telescopes were built. One telescope optic was equipped with conventional gold-coated mirrors, manufactured by the Czech project partners. The 34 X-ray mirrors of the second telescope use an innovative coating system made of chromium and iridium, which was applied at the Aschaffenburg coating laboratory. Both telescopes are designed according to the bionic principle of a reflecting lobster eye. The optics works with two consecutive reflections on mutually perpendicular mirror surfaces. This enables a large field of view with many square degrees in diameter, which, however, comes at the price of a reduced angular resolution. An extensive X-ray characterization of these telescopes was carried out at the PANTER test facility of MPE, which simulates parallel starlight incident on the telescopes. The telescopes have an angular resolution of about 4 arc minutes in X-rays and a focal length of about 2 meters. Furthermore, the used X-ray mirrors reflect and focus visible light as well and this functionality in the optical regime was checked in laboratory tests. Now another test campaign was done to examine the telescope resolution for real objects of the visible sky and the imaging properties for star constellations. Such functional tests by observing astronomical objects of the visible sky may simplify and accelerate the development of X-ray telescopes for satellite applications.}, subject = {R{\"o}ntgenteleskop}, language = {en} } @article{CotroneoBassoCivitanietal.2025, author = {Cotroneo, Vicenzo and Basso, Stefano and Civitani, Marta and D{\"o}hring, Thorsten and Gibertini, Eugenio and Iovenitti, Simone and Magagnin, Luca and Pareschi, Giovanni and Sironi, Giorgia and Spiga, Daniele and Tagliaferri, Gianpiero and Valsecchi, Giuseppe}, title = {Polydopamine Coatings for Enhanced Soft X-Ray Reflectivity in Space Telescope Mirrors}, series = {ECS Meeting Abstracts}, volume = {MA2025-02}, journal = {ECS Meeting Abstracts}, number = {67}, publisher = {The Electrochemical Society}, issn = {2151-2043}, doi = {10.1149/MA2025-02673247mtgabs}, pages = {3247 -- 3247}, year = {2025}, abstract = {It has been known for years that sputtered low-density coatings deposited under vacuum (e.g. carbon or B4C), applied on top of high-density metallic coatings, can enhance their reflectivity in the soft X-ray band (below ~5 keV). However, the physical deposition techniques, as vacuum-based sputtering, to produce B4C or amorphous coatings are usually difficult and highly costing. Polydopamine (PDA), a bio-polymer inspired by mussels, exhibits exceptional surface binding and it's nowadays a popular material used in surface engineering for multipurpose applications (Ryu, 2018). PDA thin film are typically produced in aqueous solution by the oxidative polymerization of dopamine, commonly known as one of the "hormones of happiness", resulting in nanometric PDA coating with tunable thickness and morphology. In recent years, we have introduced and investigated a novel and scalable strategy for enhancing the soft X-ray reflectivity of telescope mirrors used in space missions based on dip-liquid deposition of PDA thin films as carbon-rich coating (carbon 62.7 \%wt. in DA monomer) (Cotroneo, 2022). This method is very versatile and quick and offers a low-cost alternative to conventional carbon-like coating, while maintaining or even exceeding performance in the energy range below ~5 keV. Experimental tests across three X-ray beamlines—including two synchrotron facilities—demonstrated consistent reflectivity enhancement, especially in the 1-4 keV energy range and with a good match between theoretical predictions and experimental reflectivity profiles. When applied over traditional coatings (e.g Au, Ir), the dip-liquid overcoats produced improvements of up to 100\% in effective area for some specific X-ray bands compared to conventional single-metal films. These results are particularly compelling for nickel-replicated mirrors with gold coatings, a common architecture in cost-sensitive space missions. Bibliography Cotroneo, V., 2022. Dopamine dip-liquid overcoatings for soft x-ray reflectivity enhancement. SPIE Proceedings. Ryu, J. H., 2018. Polydopamine Surface Chemistry: A Decade of Discovery. ACS Applied Materials \& Interfaces.}, subject = {R{\"o}ntgenteleskop}, language = {en} }